Class 3, Insecta. Order 6. Lepidoptera. 275 



Others, again, are among the most deadly enemies to the cultivation of Pine- 

 trees ; the Pine-lappet {Bombyx pini) and the Black-aroh (B. monacha) . 

 Allied to the Bombycidae are the NootuidsB with bristle-like antennse (often 

 denticulate in the males), rather narrow wings, well-developed proboscis ; the 

 larvse usually naked. Certain, caterpillai-s of the Ifoctuidie (e.g., the larvae of 

 the Rustic, Agrotis segetum), ai-e often pests upon young plants, turnips, 

 potatoes, etc. 



2. The Loopers (Geonietridas) are somewhat like the Bombycidse in 

 appearance, they have broad, thin wings, bristle-like antennse (often pectinate in 

 the males). The almost naked caterpillar only possessing the hindmost paii- 

 of prolegs is very characteristic. It moves like a leech, by alternately 

 straightening and arching the body (the thoracic feet and the prolegs func- 

 tion as do the fore and hind suckers of a Leech). In some species the female 

 has more or less degenerate wings (Pig. 208). 



3. The Hawk-moths (Sphingidse). The body is short and spindle-shaped, 

 with a conical pointed abdomen, long, naiTow fore wings, small hind wings, long 

 proboscis, and pointed antennae triangulai- in cross-section. When at rest the 

 wings lie horizontally. They are large excellent fliers; the larvse are naked, 

 and the abdomen bears a curved horn. 



4. The Butterflies (Bhopalocera) have a slender body, clavate 

 antennse, and broad wings, which, when at rest, ai-e held pei-pendicularly ; 

 they exhibit beautiful, clear coloiu-s, and fly by day. The larvse often 

 possess branching, spiny outgi-owths, otherwise they ai-e naked or sparsely 

 hairy. The pupae are characterised by theii- remai-kably angular form ; usually 

 they ai-e simply attached by a single silken thread round the body, moi-e rarely 

 they lie in a loose cocoon. Two of the best known forms may be m.entioned : 

 the C a b b a g e-b utterfly {Pieris hrassicse, etc.), with white wings with small 

 dark spots (the larvae on cabbages), and the Small Tortoiseshell 

 (Vanessa vriiae), with reddish brown wings, flecked with black (the hair y 

 larvae live upon stinging nettles). 



Order 7. Diptera. 



The Diptera are holometabolous witli reduced hind 

 wings and sucking mouth-parts. The head bears a pair 

 of large eves, which, in the males, where they are best developed, 

 often touch in the mid-dorsal line. In the majority (Plies) the 

 antennse are short, and consist of only three well-developed 

 joints (of which, however, the last can usually be proved to be com- 

 posite), whilst in the Midges they are long and multiarticulate. The 

 mouth-parts are used for sucking the juices of plants or animals; 

 the chief features of their structure are given on p. 234. The three 

 thoracic segments are fused; the prothorax is small. The 

 rings of the first pair have few veiniugs, are well-developed and 

 adapted for flight ; the hind wings are reduced to halteres, which 

 are in active motion during flight; their function is not definitely 

 ascertained. The legs have long coxee, long basal joints to the 

 tarsi, and often two or three small cushions (pads) on the 

 terminal joints. The abdomen is either sessile or separated from 



T 2 



